In the past decades, Brazil made important progress in the conservation of forest ecosystems. Non-forest ecosystems (NFE), in contrast, have been neglected, even though they cover large parts of the country and have biodiversity levels comparable to forests. To avoid losing much of its biodiversity and ecosystem services, conservation and sustainable land use policies in Brazil need to be extended to NFE. A strategy for conservation of Brazil's NFE should encompass the following elements: (1) creation of new large protected areas in NFE; (2) enforcement of legal restrictions of land use; (3) extension of subsidy programs and governance commitments to NFE; (4) improvement of ecosystem management and sustainable use in NFE; and (5) improvement of monitoring of land use change in NFE. If Brazil managed to extend its conservation successes to NFE, it not only would contribute significantly to conservation of its biodiversity, but also could take the lead in conservation of NFE world-wide.
Questions: Two hypotheses were tested: (1) physical features, such as wetland surface area and habitat diversity, together with water chemistry, are important determinants of species richness and composition of macrophyte assemblages and (2) species richness and composition of macrophyte assemblages differ between wetlands of different types (i.e., palustrine versus lacustrine) and between wetlands of different hydrologies (i.e. permanent versus intermittent).
Location: A subtropical coastal plain segment (2500 km2) of southern Brazil.
Methods: Quarterly collections were carried out in 15 wetlands (2004–2005) in southern Brazil. Differences in richness over time were tested using repeated measures ANOVA. Stepwise multiple regression was performed to investigate relationships between total richness and environmental variables. Significance of differences between wetland types and hydroperiods on species composition was verified by MRPP (Multi‐Response Permutation Procedure). The influence of the environmental variables on species composition was assessed using CCA (Canonical Correspondence Analysis).
Results: Macrophyte species richness changed with time, was not significantly different between wetland types, but was higher in permanent wetlands than in intermittent ones. Area, habitat diversity and soluble reactive phosphorus concentration explained 76% of the variation in species richness. Species composition was different between permanent and intermittent wetlands, although it was not significantly different between wetland types. Area, habitat diversity and water chemistry explained 50.1% of species composition.
Conclusions: Species richness and composition of wetland macrophytes were mainly determined by area, habitat diversity and hydroperiod. These results can be used for the development of conservation and management programs in southern Brazil.
Aim We investigated the relative role of area, isolation, microhabitat diversity and number of individuals as explanatory factors defining the richness of waterbirds in wetland remnants.Location Freshwater marshes along the Atlantic coastal zone of South Brazil. (30°56′–30°22′S; 50°58–50°22′W; Fig. 1).The study area (dashed line), in the Atlantic coastal zone of Brazil, is characterized by a high concentration of remnant wetlands used by resident and migratory waterbirds. Waterbirds were surveyed monthly along 2003 in 42 randomly selected wetland remnants.imageMethods We surveyed waterbirds monthly for 1 year in 42 wetland remnants. We measured area, diversity of microhabitats, and isolation using aerial photographs and Landsat images. We compared the fit of the relationship between waterbird richness and wetland area across three models. We evaluated the ‘passive sampling effect’ comparing the observed species–area relationship with area‐based and individual‐based null models, performed with randomization without replacement. We used Path Analysis to measure the relative importance of direct and indirect effects of wetland area, isolation, microhabitat diversity and the total number of individuals on species richness.Results Power functions showed that larger wetlands had proportionally fewer species, individuals and microhabitats as compared to smaller wetlands. Species richness was consistently lower than predicted by area‐based and individual‐based random placement null models. Path analysis showed significant direct effects of remnant area and microhabitat diversity on species richness, but no effect of isolation on species richness. When number of individuals was included in the model, it became the most important factor explaining species richness, followed by wetland area. The number of individuals was significantly influenced by area, isolation and microhabitat diversity.Main conclusions We demonstrated that waterbird richness in fragmented landscapes is not a random placement phenomenon, but a biological one, significantly affected by the complex interplay of remnant area and isolation and diversity of microhabitats. We showed that the number of individuals plays a central role mediating the effect of these physical factors on species richness.
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